621306444 has 72 divisors (see below), whose sum is σ = 1598713200. Its totient is φ = 187658240.

The previous prime is 621306421. The next prime is 621306451. The reversal of 621306444 is 444603126.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 651472 + ... + 652424.

It is an arithmetic number, because the mean of its divisors is an integer number (22204350).

Almost surely, 2^621306444 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 621306444, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (799356600).

621306444 is an abundant number, since it is smaller than the sum of its proper divisors (977406756).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

621306444 is a wasteful number, since it uses less digits than its factorization.

621306444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1431 (or 1418 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 621306444 is about 24926.0194174682. The cubic root of 621306444 is about 853.3004067834.

The spelling of 621306444 in words is "six hundred twenty-one million, three hundred six thousand, four hundred forty-four".